Phytoplankton community structure of Tang-Pu Reservoir: status and ecological assessment in relation to physicochemical variability.

Seasonal variation in phytoplankton community structure within Tang-Pu Reservoir (Shaoxing city, Zhejiang province, China) was investigated in relation to variation in physicochemical and hydrological characteristics. Over the three-study seasons (autumn, winter, and spring), phytoplankton abundance and biomass showed a gradual increase with the peak in spring season. During this study period, phytoplankton community comprised of 7 phyla, 80 genera, and 210 species. The dominating phyla were Chlorophyta 80 species, Bacillariophyta 46, and Cyanophyta 44 as well as other phyla of freshwater ecosystems except Xanthophyta. The phytoplankton density and biomass varied in the six sampling sites between a minimum of 257.42 × 104 cells/L to 1054.15 × 104 cells/L and 1.60 mg/L to 4.56 mg/L respectively. Spring season had higher biomass and density values than autumn and winter. Furthermore, the results indicated that the Shannon-Wiener (H') and Pielou evenness (J') indices of phytoplankton community were stable although with slightly higher values in spring. Based on the calculated indices, Tang-Pu reservoir could be considered mesosaprobic in all the three seasons. Redundancy analysis (RDA) revealed that pH, total nitrogen (TN), total phosphorus (TP), transparency, chlorophyll a (Chl a), dissolve oxygen (DO), and water temperature (WT) were responsible for most phytoplankton community shift from Bacillariophyta and Cryptophyta to Cyanophyta and Chlorophyta in spring. These environmental parameters play an essential role in the community structure variation of phytoplankton in the downstream and upstream of Tang-Pu Reservoir. A decreasing phytoplankton abundance trend from the river area (inlet) to the lake (outlet) was also observed.

Phoenixin 14 Inhibits High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Experimental Mice.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases. The development of NAFLD is closely associated with hepatic lipotoxicity, inflammation, and oxidative stress. The new concept of NAFLD treatment is to seek molecular control of lipid metabolism and hepatic redox hemostasis. Phoenixin is a newly identified neuropeptide with pleiotropic effects. This study investigated the effects of phoenixin 14 against high-fat diet (HFD)-induced NAFLD in mice. MATERIALS AND METHODS: For this study, we used HFD-induced NAFLD mice models to analyze the effect of phonenixin14. The mice were fed on HFD and normal diet and also given phoenixin 14 (100 ng/g body weight) by gastrogavage for 10 weeks. The peripheral blood samples were collected for biochemical assays. The liver tissues were examined for HFD-induced tissue fibrosis, lipid deposition and oxidative activity including SOD, GSH, and MDA. The liver tissues were analyzed for the inflammatory cytokines and oxidative stress pathway genes. RESULTS: The results indicate that phoenixin 14 significantly ameliorated HFD-induced obesity and fatty liver. The biochemical analysis of blood samples revealed that phoenixin 14 ameliorated HFD-induced elevated circulating alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol, and triglyceride levels, suggesting that phoenixin 14 has a protective role in liver function and lipid metabolism. Hematoxylin-eosin (HE) and Oil Red O staining of the liver showed that phoenixin 14 alleviated HFD-induced tissue damage and lipid deposition in the liver. Furthermore, the mice administered with phoenixin 14 had increased hepatic SOD activity, increased production of GSH and reduced MDA activity, as well as reduced production of TNF-α and IL-6 suggesting that phoenixin 14 exerts beneficial effects against inflammation and ROS. The findings suggest an explanation of how mechanistically phoenixin 14 ameliorated HFD-induced reduced activation of the SIRT1/AMPK and NRF2/HO-1 pathways. CONCLUSION: Collectively, this study revealed that phoenixin 14 exerts a protective effect in experimental NAFLD mice. Phoenixin could be of the interest in preventive modulation of NAFLD.

[Succession of Phytoplankton Assemblages and Its Influencing Factors in Tangpu Reservoir, Zhejiang Province].

In order to explore the spatial-temporal dynamics of phytoplankton assemblages and its influencing factors in Tangpu Reservoir, phytoplankton and environmental variables were monthly monitored in 2011. The results showed that a total of 115 species of phytoplankton were identified, which belonged to 7 phyla and 62 genera. Phytoplankton abundance varied monthly with the maximum value (20.88×106 cells·L-1) in April and minimum (0.59×106 cells·L-1) in June. Variation partitioning of species data matrix showed that the variation of phytoplankton communities among months (account for 72.3%) was much larger than that among sampling sites (account for 2.5%), which indicated that phytoplankton communities had a high temporal but low spatial heterogeneity. Dominant species showed a marked seasonal succession pattern: diatom and blue-green algae species in spring, blue-green algae and green algae species in summer, diatom and cryptomonads species in autumn and winter. Result of multivariate analysis (RDA) indicated that HRT was the key factor affecting the shift between hydrological disturbance sensitive and tolerant species, and the formation of spring algal bloom; SiO2, WT and N:P were the key factors affecting the shift from diatom and cryptomonads species to blue-green algae and green algae species.